1. Field of the Invention
This invention generally relates to a methods and apparatus for brewing hot beverages from an infusible material for consumption and more particularly to a method and apparatus for brewing beverages, such as coffee and/or tea, wherein the infusible material is submerged and emerged from a brewing liquid.
2. Description of Related Art
Many methods for brewing coffee or steeping tea have emerged over time. Coffee is brewed by percolation, by infusion with water under pressure and by other methods. In one such method, coffee grounds or tea leaves, as an infusible material, are brought into contact with a large body of heated water for a predetermined time to effect the brewing or steeping of a beverage. After the infusible material is removed, the beverage is ready to be poured from a pot.
Over time certain criteria have been recognized as critical to brewing hot beverages, such as coffee and tea, successfully. Some of these criteria are outside the control of the manufacturers of beverage brewing apparatus. For example, tea drinkers control the quality and quantity of the water and tea leaves used to brew the beverage. Water quality is important to avoid any noticeable unpleasant taste that may exist when the brewing liquid is tap water with constituent metallic compounds, chlorine-containing or other compounds. Water should always be fresh; previously boiled, stagnate or distilled water should not be used. Tea leaves should be measured with care to obtain acceptable tea strength. Consumers control analogous criteria with respect to coffee in terms of a coffee brand selection, the fineness of the resulting coffee grounds and the ratio of water and coffee grounds during brewing.
Brewing apparatus can control other important criteria for successfully brewing a hot beverage. For example, apparatus can control steeping or brewing, temperature and time. As an example, the following table shows preferred steeping temperatures and times for different types of tea.
TABLEPREFERRED STEEPING TEMPERATURES AND TIMES FOR TEASRecommended SteepingRecommended SteepingTea TypeTemperature:Time:BlackWater at a full,Steep 4–6 minutes,rolling boil, (212° F.;except Darjeeling,100° C.)which should besteeped 2–3 minutes.OolongWater slightly belowVaries dramatically.boiling (190–203° F.;Many are perfect at87–95° C.).3–4 minutes. Someneed 6–8 minutes.GreenSlightly cooler2–3 minutes.water, (160–180° F.;71–82° C.).HerbalWater typically isMinimum 4–6 minutes.boiling water.Some up to 10minutes.WhiteCooler water (150–160° F.;Around 2 minutes,65–71° C.).although some can besteeped much longerwith good results.PuerhSlightly coolerAt least 7–8water, (160–180° F.;minutes. Some up to71–82° C.). Also made20 minutes.with boiling waterand steeped for along time.
Apparatus can assure several other criteria are met. For example, apparatus can be constructed to assure a brewing volume that is sufficient to enable tea leaves to expand up to three to five times in size during steeping. If the volume is insufficient for this “blooming,” the tea leaves do not fully release their flavor into the beverage. Apparatus can separate the infusible material from the beverage after brewing. Beverages that steep or brew too long may turn bitter or overly strong. Apparatus can also control and customize liquid temperature after the interval to an optimal serving temperature. As shown in the foregoing table, while the preferred brewing temperatures can be anywhere between 65° C. and 100° C. for different teas, water between 90° C. and 95° C. is best for brewing coffee. Serving temperatures for these beverages typically are in the range from 70° C. to 80° C.
In recent years, the so-called “French Press” method of brewing coffee has become a popular standard and has also been adapted for steeping tea. Apparatus for implementing this method includes a plunger with a disk made of a perforated metal mesh that fits snugly inside a glass beaker. A user removes the plunger from the glass beaker and fills the glass beaker with hot water that was heated, typically externally in a water kettle. The user then adds an appropriate quantity of coffee grounds to the water and stirs the mixture to assure proper distribution of the fusible material throughout the liquid. Then the user places the plunger assembly on top. Throughout the following brewing interval (e.g., 5 minutes), the water temperature remains fairly constant. During this brewing interval and thereafter the glass and stainless steel of the apparatus minimize any leaching of materials into the beverage that could introduce any unwanted flavor or impurity. After the user determines that an appropriate brewing interval ends, the user pushes the plunger down to the bottom of the beaker. This displaces most of the grounds toward the bottom of the beaker. Then the disk on the plunger isolates the grounds from the brewed beverage to terminate any significant brewing thereafter.
Although the French Press is a popular standard, it has certain drawbacks. This apparatus can not maintain the beverage at an appropriate serving temperature for more than a few minutes. Consequently, it is best to serve the beverage immediately upon completion of the brewing cycle. Such apparatus can be tedious to use. It requires the user to perform all the steps that are critical to the brewing of a beverage with good taste and are capable of being performed automatically. Cleaning is difficult because used grounds remain on the bottom of the beaker. The user must dispose of these used grounds and clean the beaker before the French press apparatus can be reused.
Various proposals have been made to overcome some or all of these undesirable characteristics of the original French press configuration and apparatus. For example, in U.S. Pat. No. 6,240,833 (2001) to Sham et al. an automatic French press beverage maker includes a water heater to elevate water temperature to a level that is higher than otherwise provided. After heated water is poured into a container, it is recirculated until the desired preselected temperature is reached. Then the boiled water transfers into a carafe.
U.S. Pat. No. 6,422,133 (2002) to Brady discloses a French press coffeemaker with an assembly to reduce contact of grounds with the liquid coffee after termination of a steeping period. The approach is to allow liquid to pass through the plunger more readily than with prior French press plungers and to isolate the used grounds from the coffee after the steeping period in a more complete fashion. U.S. Patent Application Publication No. 2005/0199129 (2005) to Glucksman et al. discloses an alternative structure that improves isolation. However, the remaining issues for a French press apparatus that require manual intervention including cleaning continue to exist.
With each of these French press variations, the user still needs to measure the brewing interval, move the plunger manually and clean the carafe between uses. None of the apparatuses according to these variations automatically controls any aspect of the brewing operation.
Various other apparatuses incorporate the isolation feature of French press coffeemakers, but have been developed to include some, but not all, of the criteria for brewing beverages. For example, U.S. Pat. No. 4,401,014 (1983) to McGrail et al. discloses an automatic coffee brewing apparatus in which a glass container supported on an electric heating plate includes a brew basket, or infuser. The infuser is pushed into the liquid and latched in place. The liquid is heated. An impeller in the brew basket rotates to circulate liquid through the brew basket. When the water reaches a predetermined temperature, a latch releases thermostatically and the brew basket floats up to position the spent coffee grounds above the beverage.
In U.S. Pat. No. 5,027,696 (1991) to Antononi a device for automatic brewing includes a timer. The timer controls the transport of a mesh coffee basket containing the coffee grounds from a submerged position to an emerged position through a rack and pinion drive.
U.S. Pat. No. 6,135,010 (2000) to Husted et al. discloses a coffeemaker with a computerized steeping control. A user normally lowers a filter basket into a glass coffeepot. During this operation a spring compresses and, at the end of travel, a latch engages the filter basket. When the brewing interval ends, the control energizes releasing the latch whereupon the spring moves the filter basket above the beverage.
U.S. Pat. No. 6,405,638 (2002) to Chen discloses a hot drink steeping pot with a pivoting strainer. A covered strainer carries the infusible material and immerses in the liquid in a jug. A concave lid covers the jug. When the steeping time is complete, the user manually rotates the basket 180° to nest in the lid which can then be removed and inverted to carry the grounds away from the jug.
U.S. Pat. No. 6,431,056 (2002) to Fritshi discloses a beverage infuser with a brewing receptacle and a brewing sieve that contains the material required for brewing. A mechanical-hydraulic device acts as a timer and controls the weight on the sieve which otherwise floats.
U.S. Pat. No. 6,655,261 (2003) to Horstmann discloses a tea/coffeepot with a pivoting strainer. A user fills the pot with water to an appropriate level. A strainer body including the material to be infused travels in an arcuate path to a submerged position. When the brewing time has been completed, the user moves a handle downward to retract the strainer from the liquid into an emerged position along the same arcuate path.
Each of these patents describes certain features that overcome specific shortcomings associated with the French press method, and each offers features that improve the process of steeping tea. However, none of them addresses all the issues. For example, U.S. Pat. No. 4,401,014 does not disclose concepts of temperature control and easy cleaning, although it does describe agitation by a mechanical structure that complicates manufacture and make the apparatus difficult to clean. U.S. Pat. No. 6,135,010 discusses the concept of temperature control and describes what appear to be inherent thermal currents. However, nothing in this patent or the other patents, discloses both automatic submerging and emerging of the infusible material into and from the beverage. U.S. Pat. No. 6,135,010 also does not disclose a method for removing the spent infusible material for cleaning.
Consequently, a consumer who wishes to purchase such apparatus must compromise by selecting apparatus that provides some, but not all, of the desirable criteria. What is needed is a method and apparatus for producing a hot beverage from an infusible material in which the temperature is automatically controlled to be at an optimal value during the brewing process and thereafter, wherein the liquid is agitated during brewing to assist in the extraction of flavor, wherein the spent infusible material is isolated from the beverage on completion of brewing, wherein the apparatus is adapted for easy use and cleaning and wherein the apparatus is relatively easy to manufacture.